What is BGO crystal?
Bismuth germanate crystal, namely Bi4Ge3O12, referred to as BGO, is a multifunctional scintillation crystal with good performance, colorless and transparent,
It has strong radiation blocking ability and high scintillation efficiency (It is a scintillator with the highest efficiency in detecting γ-rays), and has the advantages of not easy to deliquescence, good machining performance, etc., and is widely used in high energy physics, nuclear physics, space physics, nuclear medicine, geological exploration and other industrial fields.
The mysteries of the formation and basic structure of the universe have always been unsolved mysteries for mankind. The current consensus is that the universe was formed through the big bang. At the beginning, the temperature was very high, and there were electrons, heavy electrons, “quark” and other high-energy of small particles.
During the subsequent cooling process, these small particles gradually become protons, nuclei, and atoms. In order to explore the mysteries of the formation and evolution of the universe, it is necessary to simulate the conditions of the formation of the universe and track the conditions of small particles, so as to obtain the information of the formation of the universe.
The positron-positron collider can be used to artificially simulate the temperature of the universe when it just exploded, but those small particles cannot be observed by conventional scientific means. Therefore, a pair of special “eyes” are needed to detect these high-energy small particles.
Scintillation crystals can emit visible light under the radiation of high-energy particles (X-rays or γ-rays, etc.). Unlike other fluorescent materials (such as phosphors), scintillation crystals are huge single crystals, and the fluorescence emitted by them can penetrate the material itself.
Other fluorescent materials are just powdered crystallites, which are opaque to light. Therefore, scintillation crystals can measure the energy and position of incident particles and can be used as “eyes” for detecting high-energy particles.
BGO crystal is an ideal scintillation crystal material due to its high density, good chemical stability, insoluble in water or organic solvents, and high mechanical strength. To grow high-quality BGO crystals, the following conditions must be met: high-purity raw materials, strict ratio, harsh growth environment, and oxidizing atmosphere.
At present, BGO single crystals are mainly grown by the pulling method and the crucible descending method. Since the first GBO single crystal was successfully grown in 1965, BGO crystals have undergone leap-forward development, and have not only been widely used in the fields of high-energy physics and nuclear medicine imaging, but also played an important role in nuclear fuel scanning and geological exploration.
With the discovery of the luminescent properties of BGO, its scintillation properties and its application as a detection material for X-rays, γ-rays, positrons and charged particles have sprung up. The material basis for all these studies is to prepare BGO crystals first.
BGO crystals have occupied more than 50% of the PET market share, and crystals are also used in large-scale production of scintillator detectors in high-energy physics and space physics experiments, nuclear reactor operation monitoring and other fields.
How to simply understand BGO crystals? Let’s learn about it through a short video.
Through this video, we can clearly understand the use of BGO crystals, and what tools should be used in the process of BGO crystal processing. Many companies that produce crystals use laser cutting and external cutting to process crystals. Or the inner diameter cutting, and the wire loop cutting which came later. The wire loop cutting is in the forefront of the current technology and has been widely used in China and South Korea. For example, the Shanghai Institute of Silicate in China uses the diamond wire loop cutting technology to process BGO crystals.
With the development of science and technology, the crystal processing technology has been continuously improved. It is hoped that the development of various industries will flourish while the technology is growing.